Ratchet mechanism



May 29, 1951 L. E. KILNESS 4, 9

RATCHET MECHANISM Filed Nov. 18, 1949 2 Sheets-Sheet 1 I N VEN TOR.

y 29, 1951 4 E. KILNESS 2,554,990

RATCHET MECHANISM Filed Nov. 18, 1949 2 Sheets-Sheet 2 2O 25 as 27 29 217 18 1 Z 4 w Ii 4 2. 1' 1 I TH l4 J h 1 IN VEN TOR.

Patented May 29, 1951 UNITED STATES PATENT OFFICE j RATCHET MECHANISMLuther E. Kilness, Sioux Falls, S. Dak.

Application November 18, 1949, Serial No. 128,103

4 Claims.

This invention relates to ratchet mechanisms and has particularreference to ratchet wrenches.

The primary object of this invention is to provide 'aratchet mechanismof such high strength that the. ratchet head may be of a greatly reducedand compact size as compared to conventional Figure. 2 is a similar viewon the line 2-2 of 5 Figure5."

Figure.3 is a top view of the wrench.

Figure 4 is a sectional View taken on the line 4-4 of'Figure 5.

Figure 5 is a vertical section taken on the line 5-5-5; of Figure 4.

The wrench has a driving member comprising a handle l integrally formedwith a wrench headIlII i. The Wrench head II has a cylindrical openingto receive the head portion of a workturning. member I2. A retainingring I3 is pressed into afshouldered recess on the lower side of thehead li'l and secures the turning member I2 in the wrench head II. Theturning member is aligned in the head II by the ring l3 and by theperipheral portion of the turning member bearing against ratchet teeth Min the head II.

The {turning member I2 has two opposite concaveerecesses havingthrust-bearing ends that are curved towards radial lines on the turningmember I2. Pawls I6 are carried in the recesses I5. he pawls are shapedwith a long curved side having ratchet teeth that conform to the toothedportion of the head II and with two shorter opposing sides that conformto the ends of the recesses I5 when the pawls are in full engagementwith the teeth in the head I I. The pawls I6 are smaller than therecesses l5 and have a shorter length to permit withdrawal of the pawlsfrom the ratchet teeth I4. Every tooth on each pawl is used to drive theturning member I2 for both ratcheting directions. Each pawl engages asection of teeth in the head II having about 20% of the total number ofteeth I4.

The force transmitted to each pawl by the turning member I2 is directedperpendicularly to the radially curved ends of each recess. The momentarm of the force extends well into the outside half of the turningmember I2 and may be designed to approach the periphery of the turningmember l2. The components of the force diverge outwards on both sides topass to the individual pawl teeth. The curvature "of the teeth over thelarge section of teeth used. enables the diverging components toapproachjthe teeth at approximately right angles to the sides of theteeth. The teeth are therefore under compression on the side the forcecomponents are directed to and are capable of withstanding heavystressesefliciently.

The combination of the large number of ratchet teeth effectively usedand the large moment arms give the mechanism an exceptionally hightorque capacity. The high torque capacity permits a considerablereduction in the size of the head members and enables the ratchet to beconveniently used in places Where conventional ratchets would be toolarge.

The ratcheting motion of the pawls l6 is controlled by a reversing discII, control plates l8, and springs I9. Pins are pressed ihto small holesin the tops of the pawls and extend past slots 2| in the reversing discH, where they are terminated by rectangular projections that fit intorectangular holes in the controlplates I8.

During the ratcheting action, one end'of each spring I9 is held out ofcontact with thecontrol plates l8 by a spring guide 22 whilethe otherend of each spring I9 is free to press against a control plate [8, asshown in Figurejld. The spring guide 22 maintains the positionishown inFigure 4 relative to the spring ends until the ratchet motion isreversed by the manual control.

The ratcheting action is as follows. For illustrative purposes, theaction is described for the direction which drives the work clockwise.

The handle is turned counter-clockwise to obtain a new hold. Thispermits the springs l9, which act on the pawls l6 through the controlplates lit, to move pawl ends [6a away from the ratchet teeth I4. At thesame time, the pawls l6 are pivoted by the pins 20 as the pins contactthe inner portion of the slots 2i in the reversing disc H. The springpressure acting on the pawls tends to rotate the pawls about the pivotsprovided by the inner sides of the slots and urges pawl ends I6b againstthe ratchet teeth 14.

As the handle movement is continued in a counterclockwise direction fora new hold, the ratchet teeth I exert a frictional drag on the ,pawlends I619. The frictional force between the pawl ends I61) and theratchet teeth It causes the pawls to follow the ratchet teeth I4 untilthe pawl pins are brought against the sides of the 3 slots 2|. The pawlsare thereby prevented from following the ratchet teeth further, andcontinued back movement of the handle causes the pawl ends-[6b to engagesuccessive series of teeth of the ratchet teeth I4. I

As the handle is turned in a clockwise direction to drive the work, thepawl ends lGb are still releasably held against the ratchet teeth Ill.The pawl ends Ilia are now forced against the ratchet teeth by theconcave surfaces of recesses iii to bring all of the pawl teeth intolocking engagement with the ratchet teeth M.

The ratcheting direction is dependent on the angular position of thereversing disc IT and spring guide 22 relative to the turning member l2.Spherical detents 23 hold the reversing disc in either of two positions,depending on the ratcheting direction. The two positions of thereversing disc align the slots 2| so that the pins 20 may have pivotalsupports in both ratcheting directions. Figure 2 shows the position ofthe reversing disc for driving the work in a clockwise direction. Forturning the work in a counterclockwise direction, the slots 2! on thereversing disc must be positioned toward the other side of each recess[5. r

-The spring guide 22 has a square extension fitted to the reversing discIT to change the angular position or the spring guide for the tworatchetin directions. The ends of the spring guide intercept the ends ofthe springs l9, which are fixed to the turning member I? by extensionsfrom the center of each spring l9 that enter grooves 26 on the peripheryof the turning member. Relative motion between the spring guide 22 andthe springs i9 causes one end of each spring [9 to be withdrawn from thecontrol plate while the other end is free to actuate the control plate.Figure 4 shows the position of the spring guide for driving the work ina clockwise direction. For the counterclockwise driving direction, thespring guide intercepts the spring ends which are shown in contact withthe control plates l8 in Figure 4.

-The spherical detents 23 are contained in two diametrically spacedholes in the turning member i2. Helical springs 2% force the detents 23against the reversing disc ii. A projection 25 extending from theturning head 92 holds the "reversing disc and spring guide to theturning member i2 against the pressure of the detents 23. The sphericaldetents 23 are urged against two smaller diameter holes in the reversingdisc which are diametrically offset so that onl one detent isoperable ata time. The reversing disc is held in position by either detent to givetwo angular positions corresponding to the two ratcheting directions.

A push button 2? gives manual control of the ratchetin direction.Pressure on the push buttoniorces down a push rod 28 against a spring29. The end of the push rod is secured to a wedge 30. The downwardmovement of the push button '21 brings the wedge 36 against two balls3|, which are in a hole joining the recesses I53. The wedge 39 forcesthe balls apart and against the pawls and locks the pawls with theratchet teeth l4. With the push button in the normally up position, asshown in Figure 5, the wedge 30 is witl'idrawn from the bails 3i andpermits them to have freedom of movement in the hole joining therecesses !5. The pawl action is then unaffected by any contact that theloosely confined balls 3| may have with the pawls. In operation, theratcheting direction is sereleased.

lected by depressing the push button 21 and rotating the handle througha small arc in the direction that the work is to be driven. Depressingthe push button locks the pawls with the wrench head II, and thesubsequent rotation of the handle causes the pawls to be moved to theother end of the recesses l5. The reversing disc is shifted by the pawlpins 20 to the second operative position. The spring-pressed balls ordetents 23 are partly entered in holes in the reversing disc I! and havea holding effect on the reversing disc that is sufficient to maintainthe position of the reversing disc once reversal is effected. Duringreversal of the ratchet mechanism, the normal holding force acting onthe reversing disc is overcome by the movement of the pawls to theopposite ends of the recesses l5. The movement of the pawls brings thepawl pins 26 against the slots 2| in the reversing disc and causes thereversing disc to be rotated against the holding force of one detent 23to a new angular position where the second detent 23 may'enter one ofthe offset holes in the reversing disc. With the pawls now moved to theother ends of the recesses I5 and the reversing disc held in position bythe second detent 23, the push button ma be The driving action of theratchet mechanism is now in the same directionasthe rotation of thehandle while the push button was depressed.

While one form of the invention has been described, the invention is notlimited to theparticular structure shown except as specified in thefollowing claims, in which I claim:

1. In a ratchet mechanism, the combination of a driving member and awork-turning member, one of said members having a cylindrical openingwith inwardly extending ratchet teethv and the other having a headportion rotatably mounted in said opening, a reversible pawl carried ina concave recess on the side of the head portion, the ends of the recessbeing curved towardsradial lines on the head portion, said pawl havingtwo short sides conforming to the thrust-bearing ends of the recess anda long curved side joining the short sides made with a series of ratchetteeth, the size or" the pawl being smaller than the recess to permitwithdrawal of the pawl from engagement with the-teeth in the cylindricalopening, means for bringing every tooth on the pawl into reversible andcoacting engagement so that the combination of the simultaneousengagement of a large section of teeth in the cylindrical opening andthe radially curved ends of the recess may have a compressional forceaction on the. sides of the pawl teeth, the compression components ofeach tooth adding to a large resultant force having a large moment armin the outside half of the head portion for a maximum torque effect, andmeans for reversing the ratcheting direction.

2. In a ratchet mechanism, the combination of a driving member having acylindrical opening with inwardly extending teeth, a work-turning memberrotatably mounted in the cylindrical opening, said turning member havinga recess on one side, a reversible pawl carried in the recess, said pawlhaving two short opposing sides conforming to the ends of the recess anda long curved side joining the opposing sides made with a series ofratchet teeth conforming to the'teeth in the cylindrical opening, thelen th of the pawl being shorter thanthe distance across the ends of therecess to permit withdrawal of the pawl from engagement with the teethin the cylindrical opening, means for disengaging'one pawl end while theother pawl end is releasabl pressed against the teeth in the cylindricalopeningfas the driving member isturned back for a' 'new hold and forbringing allof the pawl teethin'to concurrent engagement with theratchet teeth i'n the cylindrical opening during the positive stroke ofthe driving member, and means for reversing the ratcheting direction. v

3. In a ratchet mechanism, the combination of a driving member hayingacylindrical opening with inwardly extending teeth, a work-turning memberrotatably mounted in the cylindrical opening, said turning' mefmberhaving al recess containing a toothed paw of smaller si'zef'tlian therecess to permit 'witfhdrawal of the pawl from the teeth inthecylindrical opening, and means for turning the p'avfvl as the drivingmember is brought back for a new hold so that the teeth on one end ofthepawl may be withdrawn from the teeth in the cylindrical opening whilethe teeth on the other end of the pawl are releasably pressed againstthe teeth in thelI'cyIindrical opening, said means cooperating with" therecess for bringing the" teeth on both pa} ends into concurrentengagement with the iratehet teeth in the cylindrical opening during thepositive stroke of the driving member. M

4. In a ratchet mechanism, the combination of a driving member having acylindrical opening with inwardly extending teeth, a work turning memberrotatably mounted in the cylindrical opening, said turning member havinga recess on one side, a reversible pawl carried in the recess, said pawlhaving two similar opposing sides conforming to the ends of the recessand a long curved side with ratchet teeth conforming to the teeth in thecylindrical opening, means for pivoting the pawl at either of t wopositions in the recess for the two ratchetingdirections, means forturning the pawl as the driving member is brought back for a new holdso; that one pawl end may be withdrawn from the teeth in the cylindricalopening while the other end of the pawl is releasably pressed againstthe teeth in the cylindrical opening, said turning means cooperatingwith the recess for bringing all of the pawl teeth into concurrentengagement with the ratchet teeth in the cylindricali'opiening duringthe positive stroke of the driving'member, and means for reversing theratcheting direction.

- LUTHER E. KILNESS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

